GE Aircraft Engines
Embraer 170/CF34-8E
FAMILIARIZATION TRAINING
CONTROL SYSTEM
Control System Design Philosophy
•
•
•
•
Redundant, engine critical electrical systems
– Dual channel FADEC (full authority digital electronic control)
– Dual cables, connectors, torque motors, solenoids and sensors
– Dual FADEC power supplies
Redundant aircraft interfaces
– Dual aircraft data busses (ARINC 429)
– Dual throttle inputs
– Dual 28 Vdc aircraft backup power
Fail operational control system
– No significant change in power for any single electrical failure from a
full up system
– Reversionary modes provide thrust for multiple failures
Time Limited Dispatch Capable
– Capable of short and long term dispatch including one FADEC channel
failed
FADEC
TR
HALF
T4.5
FADEC
A
P0 P3
T2
FADEC
B
N1
N2
MFP
OBV
VG
ACT
FMU
T4.5
P0 P3
TR
HALF
PMA
GMO
SWITCH
FADEC
Test
Connector
(J5)
Pressure Inputs
Vibe Isolated Mounts
Engine
Connectors
(J3, J4)
Aircraft
Connectors
(J1, J2)
FADEC Components
DUAL
PROCESSORS
DUAL
POWER
SUPPLIES
CROSS
CHANNEL
DATA BUS
PROCESSOR B
POWER SUPPLY B
POWER SUPPLY A
PROCESSOR A
P3 SENSORS
P0 SENSORS
PERMANENT MAGNENT ALTERNATOR (PMA)
FADEC
CONNECTIONS
STATOR
ENGINE
VENT
LINE
– Provides power for FADEC channels above 50 % N2
– Provides N2 speed signal to FADEC
– Provides N2 speed signal for Vibration System
PERMANENT MAGNENT ALTERNATOR (PMA)
STATOR
ENGINE
VENT
LINE
N2 SENSOR – MAIN FUEL PUMP
N2 SPEED SENSOR
MAIN FUEL PUMP
CONNECTIONS
TO FADEC
N2 SENSOR – MAIN FUEL PUMP
MAIN FUEL
PUMP SHAFT
MAGNETIC SENSOR
CONNECTIONS
TO FADEC
T2 FAN INLET TEMPERATURE SENSOR
FADEC
CONNECTIONS
T2
SENSOR
– Provides Temperature Input for FADEC channels
– Electrically heated for anti-ice
N1 FAN SPEED SENSOR
FADEC
CONNECTIONS
MAGNETIC
TIP
N1
SENSOR
–
–
–
–
–
Provides N1 speed signal to FADEC
Provides N1 speed signal for Vibration System
Provides once-per-rev signal for Vibration System
Picks up speed signal from teeth on no. 2 bearing locknut
One tooth on locknut is “shaved” to provide once-per-rev
N1 FAN SPEED SENSOR
COMPRESSOR
FRONT FRAME
N1 FAN SPEED
SENSOR MOUNTING
FLANGE
N1 FAN SPEED SENSOR
FAN SPEED
SENSOR
FLANGE
NO. 2 BEARING
LOCKNUT
T4.5 THERMOCOUPLES
THERMOCOUPLE
T4.5 THERMOCOUPLES
THROTTLE QUADRANT ASSEMBLY (TQA)
FORWARD THRUST
LEVER
AUTOTHROTTLE
QUICK DISCONNECT
BUTTON
REVERSE THRUST
LEVER
(PIGGYBACK)
TAKEOFF /
GO AROUND
BUTTON
MASTER
LEVER
SWITCH
START / CONTINUOUS
IGNITION BUTTON
MASTER
SELECTOR
SWITCH
ENGINE CONTROL PANEL
MASTER
LEVER
SWITCH
START / CONTINUOUS
IGNITION BUTTON
MASTER
SELECTOR
SWITCH
FADEC
FMV SERVOVALVE
IMPENDING
BYPASS
SENSOR
VG SERVOVALVE
OVERSPEED
SOLENOID
FUEL TEMP SENSOR
FMV
TRANSDUCER
FADEC
OPERABILITY VALVE
OBV VALVE
OBV EXHAUST
DUCT
10TH STAGE
BLEED DUCT
FUEL PRESSURE
LINES FROM
FUEL PUMP
FADEC
CONNECTIONS
OPERABILITY VALVE
OBV VALVE
OBV EXHAUST
VARIABLE GEOMETRY ACTUATORS
SLAVE ACTUATOR
LINEAR VARIABLE
DIFFERENTIAL
TRANSDUCER
(LVDT)
MASTER ACTUATOR
– Opens and closes variable geometry vanes in HPC
– Helps prevent compressor surges and stalls
– Fuel powered
– Master actuator has position feedback (LVDT)
VARIABLE GEOMETRY ACTUATORS
LINEAR VARIABLE
DIFFERENTIAL
TRANSDUCER
(LVDT)
MASTER ACTUATOR
CONNECTION
TO ACTUATOR
SHAFT
VARIABLE GEOMETRY ACTUATORS
ACTUATION RING
LEVER ARMS
VARIABLE GEOMETRY
ACTUATOR CONNECTION
ACTUATOR SHAFT
BRIDGE CONNECTOR
ENGINE STARTING
AIRCRAFT
CIRCUIT
CONNECTOR
IGNITION LEAD CONNECTOR
IGNITION EXCITER
•
•
•
Converts 115 VAC, 400 Hz to Pulsating DC for Engine Start
Powered by Aircraft Circuit under FADEC control
Two per engine
ENGINE STARTING
EXCITERS
IGNITION LEADS
ENGINE STARTING
IGNITER
IGNITION LEAD
ENGINE CONFIGURATION PLUG
•
•
•
•
Engine config plug allows storage of engine specific information
– Engine rating
– Engine hardware configuration
– Engine N1 modifier level
– Engine serial number
Config plug stays with engine - mounted
on fan case
Communicates stored information to
FADEC upon ground FADEC power-up
– Serial data stream clocked out of EEPROM in ECP
– FADEC conducts numerous data consistency checks
Engine config plug is field reprogrammable
ENGINE CONFIGURATION PLUG
TEST / DOWNLOAD CONNECTOR
CONNECTIONS TO FADEC
ENGINE CONFIGURATION PLUG
FADEC REPROGRAMMING
• FADEC reprogrammed using PMAT 2000
– GE option includes loader software and cable assembly
– PMAT can also be used to reprogram the engine configuration plug
• FADEC software versions may be loaded on PMAT from floppy disk or LAN for
subsequent use for FADEC reprogramming
• PMAT compares three different checksums at the end of each file load. All three
must match or the load is Aborted and Failed.
– VDD Checksum
– Imbedded Checksum
– Calculated Checksum
• PMAT generates Load Recept documenting load results
ENGINE STARTING
•
•
•
•
•
•
Start discrete from cockpit initiates starter
MAU fully controls starter
– Reads cockpit start discrete
– Energizes starter air valve solenoid
– Cuts out starter at 53% N2
Master lever controls fuel flow and ignition via the FADEC
– Throttle moved from shutoff initiates fuel flow and ignition
– fuel flow held off until 20% N2
– on ground, FADEC alternates igniters on successive starts
FADEC controls start to N2 acceleration (Ndot)
FADEC will terminate start on ground for
– hot start
– hung start
Starter air valve may be manually opened and closed
POWER MANAGEMENT
Power Management Schedules
Power management schedules are 4 dimensional (3 inputs)
Engine is flat rated to corner point day
ALTITUDE
CORRECTED N1
•
•
hot
hotday
daycutback
cutback
AIRSPEED
corner
point
OUTSIDE AIR TEMPERATURE
POWER MANAGEMENT
FAN SPEED - N1
100
90
MPR
NTO
80
MCL
N1 [%]
70
60
MREV
50
40
RIDLE
30
20
-40
IDLE
-30
-20
-10
0
TLA [deg]
10
20
30
40
Ignitor A has been commanded on
Ignitor B has been commanded on
Ignitors A and B have been commanded on
Ignitors A and B in OFF
POWER MANAGEMENT
IDLE Selection
When TL is at forward IDLE detent, different thrust schedules are available depending on flight phase:
• Flight IDLE:
is selected when WOW is false, it is determined by either min PS3, minimum
N2K or minimum WF whichever is more limiting
• Approach IDLE: is selected when WOW is false and APPROACH bit is set, it is determined
as minimum N2K to ensure acceptable IDLE - Go Around transients
• Landing IDLE:
is selected when WOW is true for less than 5 seconds and TRAS is stowed.
Its purpose is to keep N2 relatively high in order to minimize transition time to Reverse IDLE
(that is higher) without penalizing too much landing distance if TRAS is not operated
• Ground IDLE:
is selected when WOW is true for more than 5 seconds
When TL is at Reverse IDLE detent engine control is scheduled on N2K values that are defined to
keep core speed enough high to allow acceptable transition time to MAX REV thrust setting
POWER MANAGEMENT
Detent
Rating
Control Variable
MREV
Max Reverse
N1K = f(Alt, Ma)
R/IDLE
Reverse IDLE
N2K = f(Alt)
Ground IDLE
Min WF such that
N2K ≥ 61.3%
N2 ≥ 55.8%
WF ≥ 200 pph
Landing IDLE
N2K = f(Alt)
Approach IDLE
N2K = f(Alt)
IDLE
Flight IDLE
Min WF such that
PS3 ≥ f(Alt, Bleed)
N2K ≥ 64.3%
WF ≥ 200 pph
MCL
Max Climb
N1K = f(Alt, Ma, Dtamb, Bleeds)
NTO
Take Off
MPR
N1 = f(Alt, Ma, Dtamb, Bleeds)
Manual Power Reserve N1 = f(Alt, Ma, Dtamb, Bleeds)
POWER MANAGEMENT
Takeoff Thrust – Normal
N1 SPEED VARIED AS FUNCTION OF:
ALTITUDE
&
TEMPERATURE
TO MAINTAIN CONSTANT TAKEOFF
THRUST OF 12700 LBS
THRUST RATING
Selected via MCDU
Possibilities:
•TO-1, TO-2, TO-3
•CLB-1, CLB-2
•CRZ
•CON
•GA
THRUST RATING
FLEX TAKEOFF
Takeoff Thrust – Flex Takeoff
CORRECTED N1
•
•
•
Pilot sets Delta Ambient Temperature
New Temperature Sets Power Schedule Past Corner Point
Thrust Is Derated – Simulating Hot Day Cutback
hot
hotday
daycutback
cutback
Actual
OAT
Flex
OAT
POWER MANAGEMENT
Flexible Take Off Thrust
• FADEC have the capability to provide reduced thrust at NTO flat. This is obtained by pilot input of a Flex TO
Assumed Temperature.
• This temperature is used by FADEC instead of actual SAT to determine NTO thrust and is echoed back to the
cockpit
• Initial entry of a Flex TO Temperature is possible when all the following condition are met:
–
TLA at IDLE
–
WOW true for at least 1 minute
–
Airspeed < 65 Kts
• Once Accepted Flex TO Temperature can be modified until a Locking Flag is set. Lock is set when any of the
following condition occur:
–
TLA at MCL or NTO flats
–
WOW transition from True to False
–
Aircraft Speed first exceeds 65 Kts and remains above 45 Kts for more than 0.480 sec.
• Flex Mode (Lock and Temperature) is then cleared when any of the following condition occur:
–
TL moved from NTO flat (either direction)
–
APR activated
–
Airspeed > 65 Kts and TL below NTO flat
–
WAI activated
POWER MANAGEMENT
APR - Automatic Power Reserve
• This functionality provides a thrust increase on the operating engine in the event of an engine failure
• Additional thrust is provided at NTO (APR) and MCL (MXCN) detents. TLA scheduling is change
accordingly
• It is enabled and latched when both engine N1 are within 8% of NTO rating. Only local engine data is
required when APPROACH bit is set
• It is activated when
– Cross engine N1 drops 15% below local engine N1
– Cross engine Data Bus is lost
– Cross engine N1 is invalid
• It is cleared when cross engine N1 difference becomes less than 13%
• If not active, it is disabled when local N1 drops below 8% of NTO rating and:
– WOW is true and Wheel Speed < 60 KTS
– WOW is true for more than 1 minute
• APR activation can be invoked by throttles splitting
ATTCS
ATTCS ARMED
ATTCS ENGAGED
TO-1 RSV
ENGINE FAILURE DETECTED
POWER MANAGEMENT
AUTOMATIC POWER RESERVE
110
100
MXCN
APR
90
MCL
N1 [%]
80
NTO
MPR
70
60
50
APR Activated
40
All Engine Operative
30
20
-25
-15
-5
5
TLA [deg]
15
25
35
POWER MANAGEMENT
MANUAL POWER RESERVE
MPR - Manual Power Reserve
110
•
APR thrust can be manually selected by
100
advancing throttles up to MPR flat. This sets a
90
manual OEI latch that activate APR
80
MPR
NTO
•
Once MPR flat is reached, retarding throttle to
NTO flat will still provide APR thrust. MCL detent
will provide MXCN thrust as well.
N1 [%]
MCL
70
60
50
After MPR Selection
40
•
OEI latch is cleared by further retarding throttles
Before MPR Selection
30
below MCL flat
20
-25
-15
-5
5
TLA [deg]
15
25
35
Maximum thrust
available if desired by
throttle selection
FADEC
< MAIN
STATUS
ECS
CPCS
ELEC
FLIGHT
FUEL
HYDR
ICE
LIGHTS
DOORS
ENG/APU
TO 88%
87.7 %
943 °C
S
T
A
R
T
N1
87.7
ITT
944
NO
SYNC
V
I
B
IGN
REV
REV
A/I
A/I
87.9 %
N2
IGN
S
V T
I A
B R
T
88.0
OIL TEMP
OIL PRS
LINE 01 - WARNING 001
LINE 02 - WARNING 002
LINE 03 - WARNING 003
LINE 04 - WARNING 004
LINE 05 - CAUTION 001
LINE 06 - CAUTION 002
LINE 07 - CAUTION 003
LINE 08 - CAUTION 004
LINE 09 - ADVISORY 01
LINE 10 - ADVISORY 02
LINE 11 - ADVISORY 03
LINE 12 - ADVISORY 04
LINE 13 - STATUS 001
% LINE 14 - STATUS 002
LINE 15 - STATUS 003
LINE 16 - STATUS 004
LINE 17 - STATUS 005
LINE 18 - STATUS 006
LINE 19 - STATUS 001
LINE 20 - STATUS 002
LINE 21 - STATUS 003
LINE 22 - STATUS 004
LINE 23 - STATUS 005
LINE 24 - STATUS 006
APU RPM
OIL QTY
90
2,1
N1 VIB
1,7
N2 VIB
FLOW
(lbs/hr)
FUEL
3784
USED
(lbs)
7500
APU EGT
180 °C
%
3.1
2.4
NORM
FLOW
(lbs/hr)
APU DOOR
OPEN
DEICE
3788
TOTAL USED
(lbs)
15000
USED
(lbs)
7500
LINE 01 - WARNING 001
LINE 02 - WARNING 002
LINE 03 - WARNING 003
LINE 04 - WARNING 004
ENGINE STARTING
Starting Process:
1. Master Lever → ON
2. Mode Selector → RUN
3. Start Switch → ON
0%
FADEC-observed Limits
below Idle on Ground:
IGN → ON
10%
FFL → ON
20%
• Hot Start
T45 > 810°C
• Hung Start N2dot ↔ T45
• No light off N2ind → T45
Starter
Cutout
50%
N2
GI
POWER MANAGEMENT
N1 Synchronization
• This functionality provides N1 synchronization between RH and LH engine in order to accommodate
throttle stagger and reduce cabin noise
• When Synchronization is enabled the RH engine (Slave) N1 reference is biased to match LH engine
(Master) N1 reference.
• Maximum allowed bias is ± 2.36% relative to N1 reference corresponding to actual Slave TL position
• N1 Synchronization is enabled when:
– IDLE <= TLA < MCL detents
– APR not active
– No OEI indication
– Delta N1 reference between Master and Slave < 1.42%
• If delta N1 reference between Master and Slave becomes higher than ±2.36%, Slave engine N1 will
remain biased until Synchronization is disabled
• Slave engine control modes different from N1 reference (N2K, min PS3 etc.) will take priority over N1
synchronization reference
POWER MANAGEMENT
N2 Overspeed Protection
This system prevents engine core speed to overcome its overspeed threshold (102%)
• Two overspeed electronic circuit within FADEC, but independent from CPU receive N2 signal by
two different transducers.
• When both circuits detect N2 overspeed the FMU shut off solenoid is energized causing an engine
flame out. FADEC will detect flame out and turn ignition ON. When N2 falls below the overspeed
threshold, the FMU solenoid is de-energized to allow engine re-light
• The overspeed system latches fuel shut off if three N2 overspeeds are detected within 30 second
• System is tested at each ground starting and before flight and is activated at each shut down on
ground
FAULT DETECTION
Maintenance Manual Fault Isolation Page
Fault Message
Bit Code
Fault Description